codes 68 and 99

[Dewey Faircloth]

On 94 GMC suburban.have codes
68 trans slip
99 pedal position 2

Does this mean it needs a tranmission rebuilt or replaced?

Thanks,
Dewey

[charliepeterson]

I can't recall a code #68 for Trans. slipping? If the maintenance has been good on the transmission then drop the pan and filter and take it for a good ride. If the maintenance hasn't been good @ 190K your rolling the dice for future issues if you drop the pan and filter.

The other code should be a reference signal to the ECM? This might have just been a fluke. Did you see the "service throttle soon" or STS light come on? If the light stays on as a "hard" code then track down the cause.